Vsevolod Ostapenko created KYLIN-3687: -----------------------------------------
Summary: Top_N measure requires related SUM() measure to be defined as part of the cube to work, but Web UI allows creation of the cube that has Top_N measure only, resulting in NPE at query time Key: KYLIN-3687 URL: https://issues.apache.org/jira/browse/KYLIN-3687 Project: Kylin Issue Type: Improvement Components: Measure - TopN, Metadata, Web Affects Versions: v2.5.0 Environment: HDP 2.5.6, Kylin 2.5 Reporter: Vsevolod Ostapenko Web UI allows defining a cube with Top_N measure without defining a related SUM() measure. E.g. a variation of the kylin_sales_cube can be successfully defined via UI with just TOP_SELLER without actually defining GVM_SUM measure. Such cube builds just fine, but at the query time an NPE is thrown similar to the following: {quote}Caused by: java.lang.NullPointerException at org.apache.kylin.query.relnode.OLAPAggregateRel.rewriteAggregateCall(OLAPAggregateRel.java:561) at org.apache.kylin.query.relnode.OLAPAggregateRel.implementRewrite(OLAPAggregateRel.java:419) at org.apache.kylin.query.relnode.OLAPRel$RewriteImplementor.visitChild(OLAPRel.java:174) at org.apache.kylin.query.relnode.OLAPSortRel.implementRewrite(OLAPSortRel.java:86) at org.apache.kylin.query.relnode.OLAPRel$RewriteImplementor.visitChild(OLAPRel.java:174) at org.apache.kylin.query.relnode.OLAPLimitRel.implementRewrite(OLAPLimitRel.java:109) at org.apache.kylin.query.relnode.OLAPRel$RewriteImplementor.visitChild(OLAPRel.java:174) at org.apache.kylin.query.relnode.OLAPToEnumerableConverter.implement(OLAPToEnumerableConverter.java:100) at org.apache.calcite.adapter.enumerable.EnumerableRelImplementor.implementRoot(EnumerableRelImplementor.java:108) at org.apache.calcite.adapter.enumerable.EnumerableInterpretable.toBindable(EnumerableInterpretable.java:92) at org.apache.calcite.prepare.CalcitePrepareImpl$CalcitePreparingStmt.implement(CalcitePrepareImpl.java:1281) at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:331) at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:228) {quote} There need to be some checks in the UI and in the Top_N query processing code to ensure that all the required measures are defined (as Top_N is actually dependent on another measure to function properly) and inform the user that Top_N definition is incomplete and cube definition is invalid. -- This message was sent by Atlassian JIRA (v7.6.3#76005)